System, method and apparatus for fabricating a c-aperture or E-antenna plasmonic near field source for thermal assisted recording applications
View Patent ↗A method of fabricating a c-aperture or E-antenna plasmonic near field source for thermal assisted recording applications in hard disk drives is disclosed. A c-aperture or E-antenna is built for recording head applications. The technique employs e-beam lithography, partial reactive ion etching and metal refill to build the c-apertures. This process strategy has the advantage over other techniques in the self-alignment of the c-aperture notch to the c-aperture internal diameter, the small number of process steps required, and the precise and consistent shape of the c-aperture notch itself.
1. A method of fabricating a plasmonic near field source for thermal assisted recording applications in hard disk drives, the method comprising:
(a) depositing an insulator layer on a base layer;
(b) applying an e-beam resist layer on the insulator layer;
(c) performing e-beam lithography and Cr liftoff on the e-beam resist layer to form a pair of parallel hard mask features from Cr separated by a gap of approximately 30 nm;
(d) reactive ion etching (RIE) the insulator layer to form a notch therein located below the gap;
(e) performing e-beam lithography and liftoff to add a second hard mask over the gap;
(f) reactive ion etching the pair of parallel hard mask features to define edges of a structure in the insulator layer;
(g) wet etching the structure to remove extraneous hard mask material from the insulator layer;
(h) depositing a conductive layer on the structure; and then
(i) fabricating a throat of a c-aperture in the structure.
2. A method according to claim 1 , wherein step (a) comprises depositing the insulator layer as 60 nm of SiO 2 and the base layer is 300 nm of CoFe.
3. A method according to claim 1 , wherein step (b) comprises applying polymethylmethacrylate (PMMA) on the insulator layer.
4. A method according to claim 1 , wherein step (e) comprises Cr liftoff wherein a formed Cr feature completely covers the notch, but is narrower than outer edges of the pair of parallel features.
5. A method according to claim 1 , wherein step (d) comprises using CF 4 to reduce a thickness of the insulator layer outside the pair of parallel features and in the gap.
6. A method according to claim 1 , wherein step (f) enables the notch to be exactly centered between the edges of the structure.
7. A method according to claim 1 , wherein step (g) comprises wet Cr etching, such that only the notched insulator layer and the base layer remain.
8. A method according to claim 1 , wherein step (h) comprises depositing approximately 120 nm of Au on the structure.
9. A method according to claim 1 , wherein step (i) comprises defining a back wall of the c-aperture and a waveguide trackwidth by photoresist processes on the structure, and defining an air bearing surface (ABS) edge by lapping the structure.
10. A method of fabricating a plasmonic near field source for thermal assisted recording applications in hard disk drives, the method comprising:
(a) depositing an insulator layer on a base layer;
(b) applying an e-beam resist layer on the insulator layer;
(c) performing e-beam lithography and Cr liftoff on the e-beam resist layer to form a pair of parallel hard mask features from Cr in rectangular shapes separated by a gap of approximately 30 nm;
(d) reactive ion etching (RIE) the insulator layer to form a notch therein located below the gap;
(e) performing e-beam lithography and Cr liftoff to add a second hard mask over the gap, wherein a formed Cr feature completely covers the notch, but is narrower than outer edges of the pair of parallel hard mask features;
(f) reactive ion etching the pair of parallel hard mask features to define edges of a structure in the insulator layer;
(g) wet etching the structure to remove extraneous hard mask material from the insulator layer;
(h) depositing a conductive layer on the structure; and then
(i) fabricating a throat of a c-aperture in the structure.
11. A method according to claim 10 , wherein step (a) comprises depositing the insulator layer as 60 nm of SiO 2 and the base layer is 300 nm of CoFe, and step (b) comprises applying polymethylmethacrylate (PMMA) on the insulator layer.
12. A method according to claim 10 , wherein step (d) comprises using CF 4 to reduce a thickness of the insulator layer outside the pair of parallel features and in the gap.
13. A method according to claim 10 , wherein step (f) enables the notch to be exactly centered between the edges of the structure.
14. A method according to claim 10 , wherein step (g) comprises wet Cr etching, such that only the notched insulator layer and the base layer remain.
15. A method according to claim 1 , wherein step (h) comprises depositing approximately 120 nm of Au on the structure, and step (i) comprises defining a back wall of the c-aperture and a waveguide trackwidth by photoresist processes on the structure, and defining an air bearing surface (ABS) edge by lapping the structure.